Fast Fading Compensation Based on Weighted Channel Variance for TFI-OFDM

Abstract

Orthogonal frequency division multiplexing (OFDM) systems have attracted attention as the fourth generation mobile communication systems. In OFDM systems, the impact of a fading is identified by using the channel estimation (CE). However, a large number of pilot symbols is required to identify an accurate channel state information (CSI) in the conventional OFDM systems. To reduce this problem, a time frequency interferometry (TFI) for OFDM has been proposed. Under the fast fading environment, since the channel is rapidly changed, many errors are occurred. Therefore, we have proposed the fast fading compensation method by using the decision direct and linear prediction methods. However, this method has several problems. To overcome these problems, in this paper, we propose the nonlinear prediction method based on the weighted channel variance.

Estimation based on weighted channel variance for HTRCI‐MIMO/OFDM with QRM‐MLD and channel ranking under fast fading Channel

“…On the other hand, because the conventional HTRCI‐MIMO/OFDM pilot signal is inserted in the head of the packet, many errors are caused in the last part of the packet. To overcome this problem, several methods have been proposed . Shen et al .…”

“…On the other hand, because the conventional HTRCI-MIMO/OFDM pilot signal is inserted in the head of the packet, many errors are caused in the last part of the packet. To overcome this problem, several methods have been proposed [17][18][19][20][21][22][23][24][25][26]. Shen et al [17] has considered a space-time waterfilling in the fast fading environment.…”

Non-linear fast fading compensation for HTRCI-MIMO/OFDM with QRM-MLD and channel ranking

“…To overcome this problem, several methods have been proposed [2], [5], [6]. [5] has proposed the fast fading compensation by using a space time block code (STBC).…”

“…However, [2] requires large complexity due to the repeat processing. [6] has proposed the non-liner prediction method to reduce the repeat processing. However, [6] does not adopt MIMO/OFDM systems.…”

“…[6] has proposed the non-liner prediction method to reduce the repeat processing. However, [6] does not adopt MIMO/OFDM systems. Therefore, in this paper, 2 Now, he belongs to Wave Engineering Laboratories, Advanced Telecommunications Research Institute International (ATR), Japan.…”